GFS2: Split data write & wait in fsync

[pandora-kernel.git] / fs / gfs2 / file.c

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index edeb9e8..92c3db4 100644 (file)
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -551,8 +551,16 @@ static int gfs2_close(struct inode *inode, struct file *file)
  * @end: the end position in the file to sync
  * @datasync: set if we can ignore timestamp changes
  *
- * The VFS will flush data for us. We only need to worry
- * about metadata here.
+ * We split the data flushing here so that we don't wait for the data
+ * until after we've also sent the metadata to disk. Note that for
+ * data=ordered, we will write & wait for the data at the log flush
+ * stage anyway, so this is unlikely to make much of a difference
+ * except in the data=writeback case.
+ *
+ * If the fdatawrite fails due to any reason except -EIO, we will
+ * continue the remainder of the fsync, although we'll still report
+ * the error at the end. This is to match filemap_write_and_wait_range()
+ * behaviour.
  *
  * Returns: errno
  */
@@ -560,30 +568,36 @@ static int gfs2_close(struct inode *inode, struct file *file)
 static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
                      int datasync)
 {
-       struct inode *inode = file->f_mapping->host;
+       struct address_space *mapping = file->f_mapping;
+       struct inode *inode = mapping->host;
        int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
        struct gfs2_inode *ip = GFS2_I(inode);
-       int ret;
+       int ret, ret1 = 0;
 
-       ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
-       if (ret)
-               return ret;
-       mutex_lock(&inode->i_mutex);
+       if (mapping->nrpages) {
+               ret1 = filemap_fdatawrite_range(mapping, start, end);
+               if (ret1 == -EIO)
+                       return ret1;
+       }
 
        if (datasync)
                sync_state &= ~I_DIRTY_SYNC;
 
        if (sync_state) {
+               mutex_lock(&inode->i_mutex);
                ret = sync_inode_metadata(inode, 1);
                if (ret) {
                        mutex_unlock(&inode->i_mutex);
                        return ret;
                }
                gfs2_ail_flush(ip->i_gl);
+               mutex_unlock(&inode->i_mutex);
        }
 
-       mutex_unlock(&inode->i_mutex);
-       return 0;
+       if (mapping->nrpages)
+               ret = filemap_fdatawait_range(mapping, start, end);
+
+       return ret ? ret : ret1;
 }
 
 /**